Yeah, I picked up 3 of the LE Hyde Park buttondowns, but even in the tailored fit they're much too big around the waist for me. I was really disappointed after reading all the good reviews and recommendations. I've got one in at the moment getting darts put in, but I'm sceptical as to whether it can come in far enough. If it's no good I'll probably return the others (or sell it on here if anyone would be interested). They do seem to be quite good quality, although they're a bit heavier than I was expecting.
Brooks Brothers have a special on at the moment, so I picked up 2 of their extra-slim fit buttondowns in a large, after the $50 postage cost me $130ish.
On shirt alterations; As long as you're not tring to touch the shoulders / armholes / neck you can bring it in as far as you want. Note that taking it in too far via just a dart will cause balance problems.